Logic Seminar
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Thu, 19/01/2012 17:00 |
Zoe Chatzidakis (Paris) |
Logic Seminar  |
L3 |
| Recall that a difference field is a field with a distinguished automorphism. ACFA is the theory of existentially closed difference fields. I will discuss results on groups definable in models of ACFA, in particular when they are one-based and what are the consequences of one-basedness. | |||
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Thu, 26/01/2012 16:00 |
Yu V Matiyasevich (Steklov Institute of Mathematics) |
Logic Seminar Number Theory Seminar |
L3 |
| In http://logic.pdmi.ras.ru/~yumat/personaljournal/artlessmethod/artlessmethod.php the speaker described a surprising method for (approximate) calculation of the zeros of Riemann’s zeta function using terms of the divergent Dirichlet series.In the talk this method will be presented together with some heuristic “hints” explaining why the divergence of the series doesn’t spoil its use. Several conjectures about the zeros of Riemann’s zeta function will be stated including supposed new relationship between them and the prime numbers. | |||
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Thu, 02/02/2012 17:00 |
Alessandro Berarducci (Pisa) |
Logic Seminar |
L3 |
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Thu, 09/02/2012 17:00 |
Mike Prest (Manchester) |
Logic Seminar |
L3 |
| To each additive definable category there is attached its category of pp-imaginaries. This is abelian and every small abelian category arises in this way. The connection may be expressed as an equivalence of 2-categories. We describe two associated spectra (Ziegler and Zariski) which have arisen in the model theory of modules. | |||
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Thu, 16/02/2012 17:00 |
Peter Pappas (Oxford) |
Logic Seminar |
L3 |
| This talk will be accessible to non-specialists and in particular details how model theory naturally leads to specific representations of abelian group rings as rings of global sections. The model-theoretic approach is motivated by algebraic results of Amitsur on the Semisimplicity Problem, on which a brief discussion will first be given. | |||
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Thu, 01/03/2012 17:00 |
Dugald Macpherson (Leeds) |
Logic Seminar |
L3 |
| I will give an overview of the description of imaginaries in algebraically closed (and some other) valued fields, and then discuss the related issue for valued fields with analytic structure (in the sense of Lipshitz-Robinson, and Denef – van Den Dries). In particular, I will describe joint work with Haskell and Hrushovski showing that in characteristic 0, elimination of imaginaries in the `geometric sorts’ of ACVF no longer holds if restricted exponentiation is definable. | |||
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Thu, 08/03/2012 17:00 |
Logic Seminar |
L3 | |
